1. Field of the Invention
The present invention relates to the medical treatment of obesity in humans, and more particularly to apparatus and methods for curbing the appetite of persons being treated for obesity.
2. Description of the Related Art
Extreme obesity is a major health concern in the United States and other countries. Its complications may include hypertension, diabetes, coronary artery disease, stroke, congestive heart failure, venous disease, multiple orthopedic problems and pulmonary insufficiency with markedly decreased life expectancy. Medical management including dietary, psychotherapy, medications and behavioral modification techniques have not yielded exceptional results in multiple trials. Despite the declaration of obesity as a major health problem, the Centers for Disease Control reports that obesity contributes to about 400,000 deaths annually, just behind tobacco (435,000) and ahead of alcohol (85,000), car accidents (43,000) and guns (29,000). Obesity and its complications now account for an estimated 9 percent of U.S. health spending.
Non-surgical approaches for the treatment of obesity include voluntary dieting which is often unsuccessful since most persons do not possess sufficient willpower to limit the intake of food. In addition to behavioral modification, several surgical techniques have been tried which induce malabsorption by reducing the absorptive surface of the small intestine or modify the stomach to reduce a patients desire to eat. Gastric reduction surgeries in which the stomach's volume is reduced had limited early success but often the stomach's size stretches over time so these patients did not exhibit real weight for a sustained period of time. Other surgical approaches combine gastric volume reduction by either partition or bypass with a reduction in the absorptive surface of the small intestine. These procedures may be both hazardous to perform in morbidly obese patients and often create numerous life-threatening postoperative complications. Such procedures typically are invasive, require a long recuperation time and subject the patient to undue pain and discomfort. Also, such operative procedures are often difficult to reverse. These procedures are also expensive and place a large burden on the national health care system.
Other endoscopic approaches include implantation of gastric balloons that prevent overeating by occupying volume within the stomach. This fills a portion of the stomach and provides the patient with a feeling of fullness, thereby reducing food intake. Many problems are associated with the gastric balloon device, including poor patient tolerance and complications due to rupture, migration, and pressure trauma to the gastrointestinal tract. Some sham-controlled studies have failed to show that the gastric balloon was superior to diet alone in achieving weight reduction.
Other devices are designed to attempt to limit the absorption of nutrients in the duodenum by funneling the food through a tube so that the digestive process bypasses portions of the small intestine entirely. By interrupting the intermixing of the digestive fluids and/or limiting the residence period within the stomach, it is believed that the food materials will not fully digest into particles small enough to be absorbed by the body. However these devices have not been evaluated clinically.
Having made the above critical observations, the present invention further recognizes a need for a transoral endoscopic device that mediates physiologic weight loss that is easily inserted into and removed from the gastrointestinal tract, well tolerated by the patient, does not migrate, does not adversely obstruct the lumen, and does not cause tissue injury.